Liquid crystal compound, liquid crystal composition including the same and liquid crystal display including the liquid crystal composition

ABSTRACT

A liquid crystal compound represented by Formula 1:

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 10-2014-0126049, filed on Sep. 22, 2014, in the KoreanIntellectual Property Office, the disclosure of which is incorporated byreference herein in its entirety.

1. TECHNICAL FIELD

Exemplary embodiments of the present invention relate to a liquidcrystal compound, a liquid crystal composition including the liquidcrystal compound, and a liquid crystal display including the liquidcrystal composition.

2. DISCUSSION OF RELATED ART

Liquid crystal displays are generally flat, convenient to carry and havelow power consumption.

Liquid crystal displays may include two substrates with a pixelelectrode or a common electrode disposed thereon, and a liquid crystallayer disposed between the two substrates. When a voltage is applied tothe pixel electrode or the common electrode to generate an electricfield in the liquid crystal layer, the alignment of liquid crystalmolecules in the liquid crystal layer may be changed to alter thepolarization of light passing through the liquid crystal layer, andconsequently, an image may be displayed on the liquid crystal display.

SUMMARY

Exemplary embodiments of the present invention include a liquid crystalcompound, a liquid crystal composition including the liquid crystalcompound, and a liquid crystal display including the liquid crystalcomposition.

According to an exemplary embodiment of the present invention, there isprovided a liquid crystal compound represented by Formula 1:

is a group represented by Formula 10-1

are each independently selected from groups represented by Formulae 10-1to 10-12:

In Formulae 10-1 to 10-12, ″ indicates a binding site with an adjacentatom.

L₁₁, L₁₂, L₁₃, and L₁₄ are each independently selected from a singlebond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —CF₂O—, and —OCF₂.

m11, m12, and m13 are each independently selected from 0 and 1.

n11 is selected from 0, 1, 2, 3, and 4.

R₁₁ is selected from hydrogen and a C₁-C₇ alkyl group.

R₁₂ is selected from hydrogen, —F, a C₁-C₅ alkyl group, a C₁-C₅ alkoxygroup, a C₂-C₅ alkenyl group, a C₁-C₅ alkyl group substituted with —F, aC₁-C₅ alkoxy group substituted with —F, and—a C₂-C₅ alkenyl groupsubstituted with —F.

According to an exemplary embodiment of the present invention, a liquidcrystal composition includes the liquid crystal compound of Formula 1.

According to an exemplary embodiment of the present invention, a liquidcrystal display includes a first electrode, a second electrode, and aliquid crystal layer disposed between the first electrode and the secondelectrode. The liquid crystal layer includes the liquid crystalcomposition including the liquid crystal compound of Formula 1.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described more fully with reference toexemplary embodiments. Exemplary embodiments of the present inventionmay, however, be embodied in many different forms and should not beconstrued as being limited to the embodiments set forth herein.

As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise.

As used herein, when a layer, a region, or a component is referred to asbeing “on” or “above” another layer, region, or component, the layer,region, or component can be directly on another layer, region orcomponent, or intervening layers, regions or components may be present.

As used herein, “Tni” denotes a liquid crystal operating temperature. Aliquid crystal composition (or a liquid crystal compound) may undergonematic to isotropic phase transition at a liquid crystal operatingtemperature Tni or higher. A liquid crystal composition (or a liquidcrystal compound) suitable for an active matrix liquid-crystal display(AMLCD) may have a liquid crystal operating temperature Tni of about 60°C. or higher to about 120° C. The liquid crystal composition (or aliquid crystal compound) suitable for an AMLCD may be nematic in atemperature range of about −20° C. to about 120° C.

As used herein, “Δ∈” denotes dielectric anisotropy. The expression“negative dielectric anisotropy” means that Δ∈ is less than 0.

As used herein, “Δn” denotes anisotropy in refractive index. A liquidcrystal composition suitable for liquid crystal displays may have a Δnvalue of about 0.060 to about 0.300. For a twisted nematic (TN),vertical alignment (VA), in-plane switching (IPS), or fringe fieldswitching (FFS) mode LCD, the product of multiplying Δn by a cell gap(d) may be in a range of about 0.20 μm to about 0.50 μm.

As used herein, “η” denotes a flow viscosity. A smaller η may be goodfor an AMLCD. For example, a liquid crystal composition may have a flowviscosity (q) that is larger than 0 and equal to or less than 50 cP,which may be converted into a rotational viscosity (γ1) that is largerthan 0 and equal to or less than about 300 mPa·s.

As used herein, “VHR” denotes a voltage holding ratio.

According to an exemplary embodiment of the present invention, there isprovided a liquid crystal compound represented by Formula 1:

wherein, in Formula 1,

is a group represented by Formula 10-1;

are each independently selected from groups represented by Formulae 10-1to 10-12:

wherein, in Formulae 10-1 to 10-12, ″ indicates a binding site with anadjacent atom.

The groups represented by Formulae 10-2 and 10-3 may each independentlyinclude different optical isomers or one optical isomer.

For example, in Formula 1,

may be each independently selected from groups represented by Formulae10-1 to 10-7 and Formulae 10-9 and 10-12, but are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 1,

may be each independently selected from groups represented by Formulae10-1 to 10-6 and Formula 10-12, but are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 1,

may be each independently selected from groups represented by Formula10-1, Formulae 10-4 to 10-6, and Formula 10-12, but are not limitedthereto.

In an exemplary embodiment of the present invention, in Formula 1,

may be each independently selected from groups represented by Formulae10-1 and 10-4, but are not limited thereto.

In Formula 1, L₁₁, L₁₂, L₁₃, and L₁₄ may be each independently beselected from a single bond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —CF₂O—, and—OCF₂—.

In Formula 1, m11 may be selected from 0 and 1. When m11 is 0,

means a single bond.

In Formula 1, m12 may be selected from 0 and 1. When m12 is 0,

means a single bond.

In Formula 1, m13 may be selected from 0 and 1. When m13 is 0,

means a single bond,

In Formula 1, n11, which indicates the number of repetitions of CH₂, maybe selected from 0, 1, and 2. When n11 is 0, it means a single bond. Forexample, in Formula 1, n11 may be selected from 0 and 1, but is notlimited thereto.

In Formula 1, R₁₁ may be selected from hydrogen and a C₁-C₇ alkyl group.

For example, R₁₁ in Formula 1 may be selected from hydrogen, a methylgroup, an ethyl group, a propyl group, a butyl group, and a pentylgroup, but is not limited thereto.

In an exemplary embodiment of the present invention, R₁₁ in Formula 1may be selected from hydrogen, a methyl group, an ethyl group, ann-propyl group, an n-butyl group, and an n-pentyl group, but is notlimited thereto.

In an exemplary embodiment of the present invention, R₁₁ in Formula 1may be selected from hydrogen, a methyl group, an ethyl group, and ann-propyl group, but is not limited thereto.

In Formula 1, R₁₂ may be selected from hydrogen, —F, a C₁-C₅ alkylgroup, a C₁-C₅ alkoxy group, a C₂-C₅ alkenyl group, a C₁-C₅ alkyl groupsubstituted with —F, a C₁-C₅ alkoxy group substituted with —F, and—aC₂-C₅ alkenyl group substituted with —F.

For example, R₁₂ in Formula 1 may be selected from hydrogen, —F, C₁-C₆alkyl group, a C₁-C₅ alkoxy group, a C₂-C₅ alkenyl group, and a C₁-C₅alkyl group substituted with —F, but is not limited thereto.

In an exemplary embodiment of the present invention, R₁₂ in Formula 1may be selected from hydrogen, —F, a methyl group, an ethyl group, apropyl group, a butyl group, a pentyl group, a hexyl group, a methoxygroup, an ethoxy group, a propoxy group, a butoxy group, a pentoxygroup, an ethenyl group, a prophenyl group, a butenyl group, a pentenylgroup, and

-   a methyl group, an ethyl group, an n-propyl group, an n-butyl group,    an n-pentyl group, and an n-hexyl group, each substituted with —F,    but is not limited thereto.

In an exemplary embodiment of the present invention, R₁₂ in Formula 1may be selected from hydrogen, —F, a methyl group, an ethyl group, ann-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, amethoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group,an n-pentoxy group, an ethenyl group, a 1-prophenyl group, a 2-prophenylgroup, a 1-butenyl group, a 2-butenyl group, a 1-pentenyl group, a2-pentenyl group, and a methyl group, an ethyl group, an n-propyl group,an n-butyl group, an n-pentyl group, and an n-hexyl group, eachsubstituted with but is not limited thereto.

The liquid crystal compound represented by Formula 1 may also bereferred to as a “first liquid crystal compound” herein.

The first liquid crystal compound may be represented by one of Formulae1-1 to 1-3, but is not limited thereto:

wherein, in Formulae 1-1 to 1-3,

L₁₁, L₁₄, n11, R₁₁, and R₁₂ may be the same as those defined inconjunction with Formula 1.

The first liquid crystal compound may be one of Compounds 11 to 56, 67to 79, and 83 to 94, but is not limited thereto:

In Compounds 11 to 56, 67 to 79, and 83 to 94, C₃H₇ may be an n-propylgroup, C₄H₉ may be an n-butyl group, and C₅H₁₁ may be an n-pentyl group.However, exemplary embodiments of the present invention are not limitedthereto.

According to an exemplary embodiment of the present invention, a liquidcrystal composition may include any of the first liquid crystalcompounds described above.

For example, in the liquid crystal composition, the amount of the firstliquid crystal compound may be in a range of about 0.1 wt % to about 80wt %. For example, the amount of the first liquid crystal compound maybe about 1 wt % or more, about 5 wt % or more, or about 10 wt % or more,but is not limited thereto. In an exemplary embodiment of the presentinvention, the amount of the first liquid crystal compound may be about55 wt % or less, about 50 wt % or less, or about 45 wt % or less, but isnot limited thereto. In an exemplary embodiment of the presentinvention, the amount of the first liquid crystal compound may be in arange of about 5 wt % to about 30 wt %, but is not limited thereto.

When the amount of the first liquid crystal compound is within theseranges, the liquid crystal composition may have a relatively lowviscosity.

Due to the inclusion of the first liquid crystal compound, the specificresistance and voltage holding ratio (VHR) of the liquid crystalcomposition may be improved. Accordingly, a liquid crystal displayincluding the liquid crystal composition may have an increased contrast.The liquid crystal composition may be more resistant against UV rays dueto the inclusion of the first liquid crystal compound. Accordingly, aliquid crystal display including the liquid crystal compound may have anincreased yield.

The liquid crystal composition may further include a second liquidcrystal compound represented by Formula 2. However, exemplaryembodiments of the present invention are not limited thereto:

In Formula 2, R₂₁ and R₂₂ may be each independently selected from aC₁-C₇ alkyl group, a C₁-C₇ alkoxy group, and a C₂-C₇ alkenyl group;

n21, n22, and n23 may be each independently selected from 0, 1, 2, and3; and

a sum of n21, n22, and n23 may be selected from 1, 2, and 3.

In an exemplary embodiment of the present invention, when the liquidcrystal composition includes the second liquid crystal compound ofFormula 2 where the sum of n21, n22, and n23 is 1, the amount of thesecond liquid crystal compound may be in a range of about 0.1 wt % toabout 40 wt %, but is not limited thereto. When the sum of n21, n22, andn23 in Formula 2 is 1, the second liquid crystal compound may have arelatively low liquid crystal operating temperature Tni. When the sum ofn21, n22, and n23 in Formula 2 is 1 and the amount of the second liquidcrystal compound is within the above range, the liquid crystalcomposition may have a liquid crystal operating temperature Tni suitablefor commercial purposes.

In an exemplary embodiment of the present invention, when the liquidcrystal composition includes a second liquid crystal compound of Formula2 where the sum of n21, n22, and n23 is 2, the amount of the secondliquid crystal compound may be in a range of about 0.1 wt % to about 60wt %, but is not limited thereto. When the sum of n21, n22, and n23 inFormula 2 is 2 and the amount of the second liquid crystal compound iswithin this range, the liquid crystal composition may have a viscositysuitable for commercial purposes.

In an exemplary embodiment of the present invention, when the liquidcrystal composition includes the second liquid crystal compound ofFormula 2 where the sum of n21, n22, and n23 is 3, the amount of thesecond liquid crystal compound may be in a range of about 0.1 wt % toabout 30 wt %, but is not limited thereto. When the sum of n21 n22, andn23 in Formula 2 is 3, the second liquid crystal compound may have arelatively high melting point. Accordingly, when the amount of thesecond liquid crystal compound is within this range, the liquid crystalcomposition may have a relatively low degree of crystallinity.

For example, in Formula 2, R₂₁ may a C₁-C₇ alkyl group; and R₂₂ may beselected from a C₁-C₅ alkyl group and a C₁-C₅ alkoxy group. However,exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 2, R₂₁may be selected from a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, and a heptyl group; and R₂₂may be selected from a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a methoxy group, and an ethoxy group.However, exemplary embodiments of the present invention are not limitedthereto.

The second liquid crystal compound may be represented by one of Formulae2-1 to 2-4. However, exemplary embodiments of the present invention arenot limited thereto:

In Formulae 2-1 to 2-4, R₂₁, R₂₂, n21, n22, and n23 may be the same asthose defined with regard to Formula 2.

The second liquid crystal compound may be one of Compounds 100 to 142,but is not limited thereto:

In Compounds 100 to 142, C₃H₇ may be an n-propyl group, C₄H₉ may be ann-butyl group, C₅H₁₁ may be an n-pentyl group, C₆H₁₃ may be an n-hexylgroup, and C₇H₁₅ may be an n-heptyl group. However, exemplaryembodiments of the present invention are not limited thereto.

The liquid crystal composition may include a third liquid crystalcompound represented by Formula 3. However, exemplary embodiments of thepresent invention are not limited thereto:

In Formula 3, R₃₁ and R₃₂ may be each independently selected from aC₁-C₇ alkyl group, a C₁-C₇ alkoxy group, and a C₂-C₇ alkenyl group;

X₃₁ may be selected from hydrogen and —F;

n31, n32, n33, and n34 may be each independently selected from 0, 1, 2,and 3; and

a sum of n31, n32, n33, and n34 may be selected from 2, 3, and 4.

In an exemplary embodiment of the present invention, when the liquidcrystal composition includes the third liquid crystal compound ofFormula 3 where the sum of n31, n32, n33, and n34 is 2, the amount ofthe third liquid crystal compound may be in a range of about 0.1 wt % toabout 50 wt %, but is not limited thereto. When the sum of n31, n32,n33, and n34 in Formula 3 is 2 and the amount of the third liquidcrystal compound is within this range, the liquid crystal compositionmay have a liquid crystal operating temperature Tni suitable forcommercial purposes.

For example, when the liquid crystal composition includes the thirdliquid crystal compound of Formula 3 where the sum of n31, n32, n33, andn34 is 3, the amount of the third liquid crystal compound may be in arange of about 0.1 wt % to about 50 wt %, but is not limited thereto.When the sum of n31, n32, n33, and n34 is 3, and the amount of the thirdliquid crystal compound is within this range, the liquid crystalcomposition may have a viscosity suitable for commercial purposes.

For example, when the liquid crystal composition includes the thirdliquid crystal compound of Formula 3 where the sum of n31, n32, n33, andn34 is 4, the amount of the third liquid crystal compound may be in arange of about 0.1 wt % to about 30 wt %, but is not limited thereto.When the sum of n31, n32, n33, and n34 is 4, the third liquid crystalcompound may have a relatively high melting point. Accordingly, when theamount of the third liquid crystal composition is within this range, theliquid crystal composition may have a relatively low degree ofcrystallinity.

For example, in Formula 3, R₃₁ may be selected from a C₁-C₇ alkyl groupand a C₂-C₇ alkenyl group; and R₃₂ may be selected from a C₁-C₅ alkylgroup, a C₁-C₅ alkoxy group, and a C₂-C₅ alkenyl group. However,exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 3, R₃₁may be selected from a methyl group, an ethyl group, a propyl group, abutyl group, a pentyl group, a hexyl group, a heptyl group, and anethenyl group; and R₃₂ may be selected from a methyl group, an ethylgroup, a propyl group, a butyl group, a pentyl group, a methoxy group,an ethoxy group, an n-propoxy group, an ethenyl group, and a prophenylgroup. However, exemplary embodiments of the present invention are notlimited thereto.

The third liquid crystal compound may be represented by one of Formulae3-1 to 3-3, but is not limited thereto:

In Formulae 3-1 to 3-3, R₃₁, R₃₂, X₃₁, n31, n32, n33, and n34 may be thesame as those defined with regard to Formula 3.

The third liquid crystal compound may be one of Compounds 143 to 184.However, exemplary embodiments of the present invention are not limitedthereto:

In Compounds 143 to 184, C₃H₇ may be an n-propyl group, C₅H₁₁ may be ann-pentyl group, and C₇H₁₅ may be an n-heptyl group. However, exemplaryembodiments of the present invention are not limited thereto.

The absolute dielectric anisotropy value |Δ∈| of the third liquidcrystal compound may be near to zero. The third liquid crystal compoundmay be used to control a value of an anisotropy in the refractive indexΔn of the liquid crystal composition.

The liquid crystal composition may include a fourth liquid crystalcompound represented by Formula 4. However, exemplary embodiments of thepresent invention are not limited thereto:

In Formula 4,

may be each independently selected from groups represented by Formulae10-1 to 10-11;

L₄₁ and L₄₂ may be each independently selected from —CH₂CH₂—, —CH₂O—,—OCH₂—, —CF₂O—, and —OCF₂—;

R₄₁ and R₄₂ may be each independently selected from a C₁-C₇ alkyl group,a C₁-C₇ alkoxy group, and a C₂-C₇ alkenyl group;

n41 may be selected from 1, 2, and 3;

n42 to n44 may be each independently selected from 0, 1, 2, and 3; and

a sum of n42 and n44 may be selected from 1 and 2, and

″ in Formulae 10-1 to 10-20 indicates a binding site with an adjacentatom.

For example, when the liquid crystal composition includes the fourthliquid crystal compound of Formula 4 where the sum of n41 and n43 is 1,the amount of the fourth liquid crystal compound may be in a range ofabout 0.1 wt % to about 30 wt %, but is not limited thereto. When thesum of n41 and n43 in Formula 4 is 1 and the amount of the fourth liquidcrystal compound is within this range, the liquid crystal compositionmay have a liquid crystal operating temperature Tni suitable forcommercial purposes.

For example, when the liquid crystal composition includes the fourthliquid crystal compound of Formula 4 where the sum of n41 and n43 is 2,the amount of the fourth liquid crystal compound may be in a range ofabout 0.1 wt % to about 50 wt %, but is not limited thereto. When thesum of n41 and n43 in Formula 4 is 2 and the amount of the fourth liquidcrystal compound is within this range, the liquid crystal compositionmay have a viscosity suitable for commercial purposes.

For example, when the liquid crystal composition includes the fourthliquid crystal compound of Formula 4 where the sum of n41 and n43 is 3,the amount of the fourth liquid crystal compound may be in a range ofabout 0.1 wt % to about 30 wt %, but is not limited thereto. When thesum of n41 and n43 in Formula 4 is 3, the fourth liquid crystal compoundmay have a relatively high melting point. Accordingly, when the amountof the fourth liquid crystal compound is within this range, the liquidcrystal composition may have a relatively low degree of crystallinity.

For example, in Formula 4,

may be each independently selected from groups represented by Formulae10-1 and 10-6, but are not limited thereto.

For example, in Formula 4, L₄₁ and L₄₂ may be each independentlyselected from —CH₂CH₂—, —CH₂O—, and —CF₂O—, but are not limited thereto.

For example, in Formula 4, R₄₁ may be a C₁-C₅ alkyl group; and R₄₂ maybe selected from a C₁-C₅ alkyl group and a C₁-C₅ alkoxy group. However,exemplary embodiments of the present invention are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 4, R₄₁may be selected from a methyl group, an ethyl group, a propyl group, abutyl group, and a pentyl group; and R₄₂ may be selected from a methylgroup, an ethyl group, an n-propyl group, a methoxy group, an ethoxygroup, and an n-propoxy group. However, exemplary embodiments of thepresent invention are not limited thereto.

The fourth liquid crystal compound may be represented by Formula 4-1,but is not limited thereto;

In Formula 4-1, A₄₁, A₄₂, L₄₁, R₄₁, R₄₂, and n41 to n44 may be the sameas those defined with regard to Formula 4.

The fourth liquid crystal compound may be one of Compounds 185 to 199,but is not limited thereto:

In Compounds 185 to 199, C₃H₇ may be an n-propyl group.

The liquid crystal composition may include a fifth liquid crystalcompound represented by Formula 5. However, exemplary embodiments of thepresent invention are not limited thereto:

In Formula 5,

may be each independently selected from groups represented by Formulae10-1 to 10-11:

In Formulae 10-1 to 10-11, ″ indicates a binding site with an adjacentatom.

For example, in Formula 5,

may be each independently selected from groups represented by Formulae10-1 to 10-6, but are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 5,

may be each independently selected from groups represented by Formulae10-1 to 10-3, but are not limited thereto.

In an exemplary embodiment of the present invention, in Formula 5,

may be a group represented by Formula 10-1, but are not limited thereto.

In Formula 5, n51, which indicates the number of repetitions of

may be selected from 1, 2, and 3. When n51 is 2 or more, the pluralityof

s may be the same or different. For example, n51 in Formula 5 may be 1,but is not limited thereto.

In Formula 5, n52, which indicates the number of repetitions of CH₂, maybe selected from 0, 1, 2, 3, and 4. When n52 is 0, (CH₂)_(n52) means asingle bond. For example, in Formula 5, n52 may be selected from 0, 1,and 2, but is not limited thereto.

In Formula 5, R₅₁ may be selected from hydrogen, a C₁-C₅ alkyl group, aC₁-C₅ alkoxy group, and a C₂-C₅ alkenyl group, and

a C₁-C₅ alkyl group substituted with —F, a C₁-C₅ alkoxy groupsubstituted with —F, and a C₂-C₅ alkenyl group substituted with —F.

For example, R₅₁ in Formula 5 may be selected from hydrogen, a C₁-C₅alkyl group, a C₁-C₅ alkoxy group, and a C₂-C₅ alkenyl group, but is notlimited thereto.

In an exemplary embodiment of the present invention, R₅₁ in Formula 5may be selected from hydrogen, a methyl group, an ethyl group, a propylgroup, a butyl group, a pentyl group, a methoxy group, an ethoxy group,a propoxy group, a butoxy group, a pentoxy group, an ethenyl group, aprophenyl group, a butenyl group, and a pentenyl group, but is notlimited thereto.

In an exemplary embodiment of the present invention, R₅₁ in Formula 5may be selected from hydrogen, a methyl group, an ethyl group, ann-propyl group, an n-butyl group, an n-pentyl group, a methoxy group, anethoxy group, an n-propoxy group, an n-butoxy group, an n-pentoxy group,an ethenyl group, a 1-prophenyl group, a 2-prophenyl group, a 1-butenylgroup, a 2-butenyl group, a 1-pentenyl group, and a 2-pentenyl group,but is not limited thereto.

In an exemplary embodiment of the present invention, R₅₁ in Formula 5may be selected from a methyl group, an ethyl group, an n-propyl group,a methoxy group, an ethoxy group, an n-propoxy group, an ethenyl group,and a 1-prophenyl group, but is not limited thereto.

In Formula 5, R₅₂ may be selected from hydrogen and a C₁-C₅ alkyl group.

For example, R₅₂ in Formula 5 may be selected from hydrogen, a methylgroup, an ethyl group, a propyl group, a butyl group, and a pentylgroup, but is not limited thereto.

In an exemplary embodiment of the present invention, R₅₂ in Formula 5may be selected from hydrogen, a methyl group, an ethyl group, ann-propyl group, an n-butyl group, and an n-pentyl group, but is notlimited thereto.

In an exemplary embodiment of the present invention, R₅₂ in Formula 5may be selected from hydrogen, a methyl group, an ethyl group, and ann-propyl group, but is not limited thereto.

In Formula 5, when R₅₁ and R₅₂ are each independently selected from theabove-listed substituents, the liquid crystal composition may have arelatively low viscosity and a relatively low volatility.

The fifth liquid crystal compound may be represented by Formula 5-1.However, exemplary embodiments of the present invention are not limitedthereto:

In Formula 5-1, R₅₁, R₅₂, and n52 may be the same as those defined inconjunction with Formula 5.

The fifth liquid crystal compound may be one of Compounds 200 to 224,but is not limited thereto:

In Compounds 200 to 224, C₃H₇ may be an n-propyl group, C₄H₉ may be ann-butyl group, and C₅H₁₁ may be an n-pentyl group. However, exemplaryembodiments of the present invention are not limited thereto.

In the liquid crystal composition, the amount of the fifth liquidcrystal compound may be in a range of about 0 wt % to about 60 wt %.When the amount of the fifth liquid crystal compound is within thisrange, the liquid crystal composition may be highly reliable and mayhave a relatively high VHR at a relatively low viscosity. For example,the amount of the fifth liquid crystal compound may be 40% or less.

The first liquid crystal compounds, the second liquid crystal compounds,the third liquid crystal compounds, the fourth liquid crystal compounds,and the fifth liquid crystal compounds described above may be obtainedusing known organic synthesis methods.

For example, the first liquid crystal compound may be synthesized usinga method disclosed in Japanese Application Publication 1994-192142, thedisclosure of which is incorporated by reference herein in its entirety.

The liquid crystal composition may be prepared using a known method. Forexample, the liquid crystal composition may be prepared by dissolvingsuch liquid crystal compounds as described above at relatively hightemperatures. The liquid crystal composition may be prepared by mixingsuch liquid crystal compounds as described above with an organic solventsuch as acetone, chloroform, or methanol, and then removing the organicsolvent.

The liquid crystal composition may include an additive, if desired. Forexample, the liquid crystal composition may include at least oneselected from a chiral agent, a polymerizable additive, and astabilizing agent. However, exemplary embodiments of the presentinvention are not limited thereto.

The chiral agent may increase the presence of a desired directionalorientation of the liquid crystal compound. When the liquid crystalcomposition further includes the chiral agent, the liquid crystalcomposition may be an electrically controlled birefringence (ECB) modeliquid crystal composition or a dynamic scattering (DS) mode liquidcrystal composition.

In the liquid crystal composition, the amount of the chiral agent may bein a range of about 0.01 wt % to about 30 wt %, in consideration ofpreparation costs of the liquid crystal composition, but is not limitedthereto.

Non-limiting examples of the chiral agent are the compounds representedby the following formulae:

For example, the chiral agent may be selected from Compounds 225 to 232,but is not limited thereto:

In Compounds 225 to 232, m may be selected from 2, 3, 4, 5, 6, 7, 8, 9,10, 11 and 12; and n may be selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, and 12. For example, in Compounds 225 to 232, m may be selected from2, 3, 4, 5, 6, 7, 8, 9, and 10; and n may be selected from 1, 2, 3, 4,5, 6, 7, 8, 9, and 10. However, exemplary embodiments of the presentinvention are not limited thereto.

In the liquid crystal composition, the amount of the polymerizableadditive may be in a range of about 0.01 wt % to about 20 wt %, but isnot limited thereto. When the liquid crystal composition includes apolymerizable additive, the liquid crystal composition may be used in aliquid crystal display such as a polymer stabilized vertical alignment(PSVA) mode liquid crystal display that controls alignment of liquidcrystal molecules through light irradiation.

For example, the polymerizable additive may be Compound 233, but is notlimited thereto:

In Compound 233, P¹ and P² may be each independently selected from anacrylate group, a methacrylate group, a vinyl group, a vinyloxy group,and an epoxy group.

For example, P¹ and P² in Compound 233 may be each independentlyselected from an acrylate group and a methacrylate group, but are notlimited thereto.

In the liquid crystal composition, the amount of the stabilizing agentmay be in a range of about 0.0001 wt % to about 5 wt %, but is notlimited thereto. For example, the amount of the stabilizing agent may bein a range of about 0.001 wt % to about 1 wt %, but is not limitedthereto.

For example, the stabilizing agent may be an antioxidant, but is notlimited thereto, Non-limiting examples of the antioxidant are Compounds234 to 239.

In Compounds 234 to 239, R may be selected from hydrogen, a C₁-C₁₈ alkylgroup, a C₁-C₁₈ alkoxy group, and a C₂-C₁₈ alkenyl group, and

a C₁-C₁₈ alkyl group, a C₁-C₁₈ alkoxy group, and a C₂-C₁₈ alkenyl group,each substituted with at least one of a halogen atom and a cyano group.

For example, the stabilizing agent may be a hindered amine lightstabilizer (HALS) available from ADEKA Corporation, but is not limitedthereto. Non-limiting examples of the HALS are LA-52(tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate),LA-57(tetrakis(2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate),and LA-72 (bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate).

The liquid crystal composition may include a liquid crystal compoundwith positive dielectric anisotropy, unless the liquid crystal compoundwith positive dielectric anisotropy damages desired physical propertiesof the liquid crystal composition.

The liquid crystal composition may be suitable for an AM-LCD, but is notlimited thereto. The liquid crystal composition may have a negativedielectric anisotropy.

According to an exemplary embodiment of the present invention, theliquid crystal display may include a first electrode, a secondelectrode, and a liquid crystal layer disposed between the firstelectrode and the second electrode. The liquid crystal layer may includeany of the liquid crystal compositions according to the above-describedembodiments.

The liquid crystal display may be an in-plane switching (IPS) modeliquid crystal display, a fringe field switching (FFS) mode liquidcrystal display, a plane-to-line switching (PLS) mode liquid crystaldisplay, a vertical alignment (VA) mode liquid crystal display, astabilized vertical alignment (SVA) mode liquid crystal display, or apolymer stabilized vertical alignment (PSVA) mode liquid crystaldisplay, but is not limited thereto.

The liquid crystal display may include at least one alignment layerbetween the first electrode and the liquid crystal layer, and/or analignment layer between the liquid crystal layer and the secondelectrode.

In an exemplary embodiment of the present invention, the liquid crystaldisplay including any of the liquid crystal compounds according to theabove-described embodiments may have appropriate desired negativedielectric constant, a relatively low viscosity, a relatively highspecific resistance, and a relatively high VHR.

As used herein, a C₁-C₇ alkyl group may refer to a monovalent linear ora branched C₁-C₇ aliphatic hydrocarbon group. Examples of the C₁-C₇alkyl group include a methyl group, an ethyl group, a propyl group, aniso-a butyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, and a hexyl group.

As used herein, a C₁-C₇ alkoxy group may refer to a monovalent grouprepresented by —OA₁₀₁ (where A₁₀₁ is a C₁-C₇ alkyl group). Examples ofthe C₁-C₇ alkoxy group include a methoxy group, an ethoxy group, and anisopropoxy group.

As used herein, a C₂-C₁₈ alkenyl group may refer to a group with atleast one carbon-carbon double bond in the middle or at a terminal ofthe C₂-C₁₈ alkyl group. Examples of the C₂-C₁₈ alkenyl group include anethenyl group, a prophenyl group, and a butenyl group.

Exemplary embodiments of the present invention will now be described inmore detail with reference to the following examples. However, theseexamples are only for illustrative purposes and are not intended tolimit the scope of the exemplary embodiments of the present invention.

EXAMPLES Synthesis Example 1 Synthesis of Compound 22

Compound 22 was synthesized according to Reaction Scheme 1:

Compound 22 was found to have a purity of about 99.7% by gaschromatography (GC) and had a water content of about 215 ppm. As aresult of phase transition temperature by differential scanningcalorimetry (DSC), Compound 22 had a melting point of about 55.6° C.,and appeared as white crystals at room temperature.

Fluorination in Reaction Scheme 1 may be performed with, for example,SeF₄, Deoxo-Fluor®, 1,1,2,2-tetrafluoroethyl-N,N-dimethylamine (TFEDMA),XtalFluor-E®, or XtalFluor-M®, instead of diethylaminosulfur trifluoride(DAST).

Evaluation Example 1

Dielectric anisotropy (Δ∈), operating temperature (Tni) and viscosity(η) values of Compounds 21, 22, and 102, and Compounds A and B weremeasured according to a method described in Table 3. The results areshown in Table 1.

TABLE 1 Viscosity (η) Compound Δε Tni (mPa · s) Compound 21 −9.00 −17.235.6 Compound 22 −8.43 −14.7 30.5 Compound 102 −5.77 −2.7 17.8 CompoundA 0.45 −25.3 58.3 Compound B 2.8 −36.5 53

Referring to Table 1, Compounds 21 and 22 were found to have relativelysmall dielectric anisotropy (Δ∈) values, compared to Compound 102 andCompounds A and B. Dipole moments in Compounds A and B, may be generateddue to fluorine substituted to the alkyl group in Compounds A and B, andwere found to be at about 45° with respect to the major axis of each ofCompounds A and B by using Mopac7. The difference in direction betweenthe dipole moment generated due to fluorine substituted to the phenylenegroup of each of Compounds A and B and the dipole moment generated dueto fluorine substituted to the alkyl group thereof may cause relativelysmall sums of the dipole moments in Compounds A and B and relativelysmall dielectric anisotropy absolute (|Δ∈|) values in Compounds A and B.In Compounds 21 and 22, due to the substitution of cyclohexylene withfluorine substituted alkyl group, the dipole moment generated due tofluorine substituted to the alkyl group was about 90° with respect tothe major axis of Compounds 21 and 22, which may cause large sums of thedipole moments in Compounds 21 and 22 and large dielectric anisotropyabsolute (|Δ∈|) values in Compounds 21 and 22.

Compounds 21 and 22 were also found to have smaller viscosities thanCompounds A and B, because Compounds A and B include more substitutedfluorines and have higher molecular weights due to an increased lengthof the fluorine substituted alkyl group.

Examples 1 to 8 and Comparative Examples 1 and 2 Preparation of LiquidCrystal Compositions

Liquid crystal compositions of Examples 1 to 8 and Comparative Examples1 and 2 were prepared by mixing predetermined amounts of liquid crystalcompounds as described in Table 2.

TABLE 2 Example Liquid crystal compound Amount (wt %) Example 1 Compound101 18 Compound 102 18 Compound 106 22 Compound 108 22 Compound 22 20Example 2 Compound 102 18 Compound 106 22 Compound 108 22 Compound 14620 Compound 18 18 Example 3 Compound 101 18 Compound 102 18 Compound 10822 Compound 146 22 Compound 43 20 Example 4 Compound 143 12 Compound 1509 Compound 219 10 Compound 18 12 Compound 21 13 Compound 40 12 Compound43 13 Example 5 Compound 102 5 Compound 106 12 Compound 107 10 Compound108 12 Compound 143 15 Compound 144 11 Compound 146 10 Compound 150 10Compound 21 15 Example 6 Compound 120 20 Compound 143 14 Compound 144 10Compound 179 11 Compound 191 10 Compound 18 10 Compound 40 10 Compound51 15 Example 7 Compound 143 15 Compound 144 11 Compound 150 10 Compound179 15 Compound 18 14 Compound 21 13 Compound 40 11 Compound 43 11Example 8 Compound 105 8 Compound 106 8 Compound 112 5 Compound 115 9Compound 122 16 Compound 137 8 Compound 143 10 Compound 144 6 Compound150 5 Compound 22 7 Compound 203 3 Compound 219 15 Comparative Example 1Compound 101 18 Compound 102 18 Compound 106 22 Compound 108 22 Compound146 20 Comparative Example 2 Compound 101 18 Compound 102 18 Compound106 22 Compound 108 22 Compound A 20

Evaluation Example 2

Each of the liquid crystal compositions of Examples 1 to 8 andComparative Examples 1 and 2 was injected into a vertically alignedliquid crystal cell to evaluate the liquid crystal operating temperatureTni, the dielectric anisotropy value Δ∈, a refractive anisotropy value(Δn), the viscosity (η), and the VHR thereof according to the methodsdescribed in Table 3. The results are shown in Tables 4 and 5.

TABLE 3 Tni Tni was measured using a polarizing microscope equipped witha hot stage while a heating/cooling rate was maintained at about 2°C./min. Δε A homeotropically aligned liquid crystal cell and ahomogeneously aligned liquid crystal cell were manufactured using eachof the liquid crystal compositions at 20° C. and 60 Hz by using a system(Model 6254, available from Toyo Co.) to determine ε ∥ (dielectricconstant in a direction parallel to the symmetry axis) and ε⊥(dielectric constant in a direction perpendicular to the symmetry axis).Δε was calculated using the equation (Δε = ε ∥ − ε⊥) Δn Anisotropy inrefractive index(Δn) of liquid crystals to normal light and abnormallight were measured at 20° C. using an Abbe refractometer and aninterference filter (589 nm) η A viscosity (η) was measured at 25° C.using an E-type viscometer VHR A VHR was measured using a 1-inchvertically aligned (60° C.) (VA) test cell with a VA layer (availablefrom JSR Corporation) on an ITO substrate by an area method at 60° C.with a holding time of about 16.6 msec. VHR A VHR was measured afterradiation of UV light (15 J) onto after UV a 1-inch VA test cell with aVA layer (available from JSR irradiation Corporation) on an ITOsubstrate, by an area method at 60° C. (60° C.) with a holding time ofabout 16.6 msec.

TABLE 4 Exam- Exam- Exam- Exam- Exam- ple 1 ple 2 ple 3 ple 4 ple 5 Tni(° C.) 62.6 76 76 78 82 Δε −6.3 −5.2 −5.2 −5.5 −3.1 Δ n 0.098 0.0860.087 0.083 0.075 Viscosity η 25 23 23 24 16 (mPa · s) VHR (%) 98.8 — —98.8 98.7 VHR after UV 97.5 — — 97.4 97.6 irradiation (15 J)

TABLE 5 Compar- Compar- ative ative Exam- Exam- Exam- Exam- Exam- ple 6ple 7 ple 8 ple 1 ple 2 Tni (° C.) 76 76 74 78 64 Δε −3.9 −3.9 −3.2 −4.8−4.7 Δ n 0.130 0.107 0.109 0.086 0.095 Viscosity η 19 15 17 23 28 (mPa ·s) VHR (%) 98.3 98.4 98.9 96.5 96.6 VHR after UV 96.2 97.1 97.5 82.590.3 irradiation (15 J)

Referring to Tables 4 and 5, the liquid crystal compositions of Examples1 to 8 were found to have higher reliability than the liquid crystalcompositions of Comparative Examples 1 and 2.

Example 9

Compound 233 was added to the liquid crystal composition of Example 7 tobe about 0.3 wt % of a final mixture composition, followed by UVirradiation to thereby manufacture a 55-inch PSVA mode TV having apretilted angle of about 88°.

(wherein, in Compound 233, P¹ and P² are acrylate groups.)

Evaluation Example 3

A response rate of the liquid crystal composition of Example 9 wasevaluated at an operating voltage of about 8V with a cell gap of about3.1 μm. The response rate of the liquid crystal composition wasdetermined by measuring a rising time (T_(on)) and a falling time(T_(off)). As a result, the liquid crystal composition of Example 9 wasfound to have a response rate (T_(on)+T_(off)) of about 12.5 ms, whichwas a higher response rate than the liquid crystal composition ofExample 7.

Example 10

An 8-inch FFSmode TABLET panel was manufactured using the liquid crystalcomposition of Example 7. The panel had a cell gap of about 3.0 μm,pixels per inch of about 300 ppi, and a driving voltage of about 5.0V.

Evaluation Example 4

A VHR and afterimages of the panel of Example 9 (55-inch PSVA mode TV)were evaluated. The VHR measurement was performed using a VHRmeasurement system (available from Toyo Technica, Inc., at about 25 witha square wave voltage of about ±5V, a pulse interval of about 60μseconds, and a frame time of about 16.7 seconds at 30 Hz per frame. Theafterimage evaluation was performed by observing afterimages displayedon a display region after applying a checker flag on the display regionat about 50° C. for about 168 hours.

As a result, the panel including the liquid crystal composition ofExample 9, was found to have an improved VHR and exhibit lessafterimages.

As described above, according to one or more of the above exemplaryembodiments of the present invention, the liquid crystal compositionincluding one or more of the liquid crystal compound of Formula 1 mayhave relatively low viscosity, suitable refractive anisotropy, anegative dielectric anisotropy, and may be stable against UV light orheat. The liquid crystal display including one or more of the liquidcrystal compositions may have an improved VHR and exhibit lessafterimages.

While the present invention has been shown and described with referenceto the exemplary embodiments thereof, it will be apparent to those ofordinary skill in the art that various changes in form and detail may bemade thereto without departing from the spirit and scope of the presentinvention as defined by the following claims.

What is claimed is:
 1. A liquid crystal compound represented by Formula1:

wherein

is a group represented by Formula 10-1;

are each independently selected from groups represented by Formulae 10-1to 10-12:

L₁₁, L₁₂, L₁₃, and L₁₄ are each independently selected from a singlebond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —CF₂O—, and —OCF₂—; m11, m12, and m13are each independently selected from 0 and 1; n11 is selected from 0, 1,2, 3, and 4; R₁₁ is selected from hydrogen and a C₁-C₇ alkyl group; andR₁₂ is selected from hydrogen, —F, a C₁-C₅ alkyl group, a C₁-C₅ alkoxygroup, a C₂-C₅ alkenyl group, a C₁-C₅ alkyl group substituted with —F, aC₁-C₅ alkoxy group substituted with —F, and—a C₂-C₅ alkenyl groupsubstituted with —F.
 2. The liquid crystal compound of claim 1, wherein

are each independently selected from groups represented by Formulae 10-1to 10-7, Formula 10-9, and Formula 10-12:


3. The liquid crystal compound of claim 1, wherein

are each independently selected from groups represented by Formulae 10-1to 10-6, and Formula 10-12:


4. The liquid crystal compound of claim 1, wherein

are each independently selected from groups represented by Formulae 10-1and 10-4:


5. The liquid crystal compound of claim 1, wherein R₁₁ is selected fromhydrogen, a methyl group, an ethyl group, and an n-propyl group.
 6. Theliquid crystal compound of claim 1, wherein R₁₂ is selected fromhydrogen, a methyl group, an ethyl group, an n-propyl group, an n-butylgroup, an n-pentyl group, an n-hexyl group, a methoxy group, an ethoxygroup, an n-propoxy group, an n-butoxy group, an n-pentoxy group, anethenyl group, a 1-propenyl group, a 2-propenyl group, a 1-butenylgroup, a 2-butenyl group, a 1-pentenyl group, a 2-pentenyl group, and amethyl group, an ethyl group, an n-propyl group, an n-butyl group, ann-pentyl group, and an n-hexyl group, each substituted with —F.
 7. Theliquid crystal compound of claim 1, wherein the liquid crystal compoundis represented by one of Formulae 1-1 to 1-3:

wherein, in Formulae 1-1 to 1-3,

L₁₁, L₁₄, n11, R₁₁, and R₁₂ are as defined in Formula
 1. 8. The liquidcrystal compound of claim 1, wherein the liquid crystal compound is oneof Compounds 11 to 56, 67 to 79, and 83 to 94:

wherein, in Compounds 11 to 56, 67 to 79, and 83 to 94, C₃H₇ is ann-propyl group, and C₄H₉ is an n-butyl group.
 9. A liquid crystalcomposition comprising the liquid crystal compound of claim
 1. 10. Theliquid crystal composition of claim 9, wherein the amount of the liquidcrystal compound is in a range of about 0.1 wt % to about 80 wt %. 11.The liquid crystal composition of claim 9, further comprising a secondliquid crystal compound represented by Formula 2:

wherein R₂₁ and R₂₂ are each independently selected from a C₁-C₇ alkylgroup, a C₁-C₇ alkoxy group, and a C₂-C₇ alkenyl group; n21, n22, andn23 are each independently selected from 0, 1, 2, and 3; and a sum ofn21, n22, and n23 is selected from 1, 2, and
 3. 12. The liquid crystalcomposition of claim 11, wherein the second liquid crystal compound isone of Compounds 100 to 142:

wherein, in Compounds 100 to 142, C₃H₇ is an n-propyl group, C₅H₁₁ is ann-pentyl group, and C₇H₁₅ is an n-heptyl group.
 13. The liquid crystalcomposition of claim 9, further comprising a third liquid crystalcompound represented by Formula 3:

wherein R₃₁ and R₃₂ are each independently selected from a C₁-C₇ alkylgroup, a C₁-C₇ alkoxy group, and a C₂-C₇ alkenyl group; X₃₁ is selectedfrom hydrogen and —F; n31, n32, n33, and n34 are each independentlyselected from 0, 1, 2, and 3; and a sum of n31, n32, n33, and n34 isselected from 2, 3, and
 4. 14. The liquid crystal composition of claim13, wherein the third liquid crystal compound is one of Compounds 143 to184:

wherein, in Compounds 143 to 184, C₃H₇ is an n-propyl group, C₅H₁₁ is ann-pentyl group, and C₇H₁₅ is an n-heptyl group.
 15. The liquid crystalcomposition of claim 9, further comprising a fourth liquid crystalcompound represented by Formula 4:

wherein

are each independently selected from groups represented by Formulae 10-1to 10-11;

L₄₁ and L₄₂ are each independently selected from —CH₂CH₂—, —CH₂O—,—OCH₂—, —CF₂O—, and —OCF₂—; R₄₁ and R₄₂ are each independently selectedfrom a C₁-C₇ alkyl group, a C₁-C₇ alkoxy group, and a C₂-C₇ alkenylgroup; n41 is selected from 1, 2, and 3; n42 to n44 are eachindependently selected from 0, 1, 2, and 3; and a sum of n42 and n44 isselected from 1 and
 2. 16. The liquid crystal composition of claim 15,wherein the fourth liquid crystal compound is one of Compounds 185 to199:


17. The liquid crystal composition of claim 9, further comprising afifth liquid crystal compound represented by Formula 5:

wherein

are each independently selected from groups represented by Formulae 10-1to 10-11;

n51 is selected from 1, 2, and 3; n52 is selected from 0, 1, 2, 3, and4; R₅₁ is selected from hydrogen, a C₁-C₅ alkyl group, a C₁-C₅ alkoxygroup, a C₂-C₅ alkenyl group, a C₁-C₅ alkyl group substituted with —F, aC₁-C₅ alkoxy group substituted with —F, and a C₂-C₅ alkenyl groupsubstituted with —F; and R₅₂ is selected from hydrogen and a C₁-C₅ alkylgroup.
 18. The liquid crystal composition of claim 17, wherein the fifthliquid crystal compound is one of Compounds 200 to 224:

wherein, in Compounds 200 to 224, C₃H₇ is an n-propyl group, C₄H₉ is ann-butyl group, and C₅H₁₁ is an n-pentyl group.
 19. The liquid crystalcomposition of claim 9, further comprising at least one selected from achiral agent, a polymerizable additive, and a stabilizing agent.
 20. Aliquid crystal display comprising: a first electrode; a secondelectrode; and a liquid crystal layer disposed between the firstelectrode and the second electrode, wherein the liquid crystal layercomprises the liquid crystal composition of claim 9.